The present invention relates to devices and supports for stretching a human leg. More particularly, the present invention pertains to devices used for supporting a leg while applying flexion or extension forces of the type used for rehabilitating or exercising a knee joint.
Devices for stretching joints are commonly used by physical therapists for knee rehabilitation following injury or operation. A patient typically must undergo a physical therapy rehabilitation program for several weeks or months following such an event. During rehabilitation, the patient generally performs stretching exercises multiple times a day to develop strength and flexibility for the affected joint. Typically, a patient may undergo at least two types of knee rehabilitation exercises.
Flexion of the leg occurs by bending the knee joint to decrease the angle between the upper and lower portions of the leg. Flexion force is typically applied to a patient's leg by a physical therapist. During a flexion exercise, the patient lies face-up on a therapy table or other surface while a therapist applies force to the lower leg, bending it about the knee joint toward the upper leg. A structure may be placed under the knee to support the leg during flexion. Once the lower leg and upper leg are oriented at an optimal stretching angle, usually less than ninety degrees, the therapist then attempts to maintain the applied force and hold the leg at a static angle for a period of time, ranging from a few seconds to a few minutes. After the desired time has elapsed, the physical therapist then releases the applied flexion force in a controlled manner, and the leg is extended to a more relaxed position. This type of flexion exercise may be repeated several times during a single therapy session.
Similarly, extension exercises are typically also required for rehabilitation following a knee injury or operation. Extension of the leg occurs by straightening the leg at the knee joint, causing the angle between the upper and lower leg to increase. During an extension exercise, a physical therapist typically holds the lower portion of the leg or the foot of the patient in an elevated position while the patient lies face-up on a therapy table. The therapist then pushes the knee or upper part of the leg downward toward the table, causing the leg to straighten. When the leg is straightened to an optimal stretching angle, the therapist then attempts to statically maintain that position for a period of time. After the stretch is complete, the therapist then slowly releases the extension force applied to the leg, allowing the leg to return to a natural, relaxed position. This stretching exercise may also be repeated several times during a therapy session.
Devices for application of flexion or extension pressure to a patient's leg are known in the art. Such devices are commonly capable of providing either flexion or extension pressure, but not both. Such devices are also typically mounted to a table, and are not portable for use in a user's home. Also, rehabilitation therapy often requires a patient to visit a therapist's office several times a week. These trips can interfere with a patient's personal or work schedule and can create additional expense. A portable, easy-to-use stretching device would reduce the need for frequent visits to a therapist's office by allowing a user to perform flexion and extension exercises at home. A single portable device capable of providing both flexion and extension pressure without requiring extensive adjustment between modes is desired.
The application of flexion or extension force to the patient's leg can cause severe pain to the patient. During stretching, the therapist must communicate with the patient to avoid applying excessive force. The force feedback loop between the patient and the therapist necessarily causes fluctuation in the magnitude of applied pressure. Even minor fluctuations in the applied pressure, can detract from the rehabilitative effect of the exercise. Rapid or unsteady changes in applied force can cause injury to the patient. For optimal effectiveness, steady force application and steady force release are preferred. A device that allows the patient to control the applied force during both stretching and release is desired.
What is needed, then, is a device a patient can use at home, or a physical therapist can use in an office on a therapy table, to provide controlled application and release of flexion and extension forces for knee rehabilitation exercises.